Process of producing printing-cliches and high-reliefs.



UNTTE STATES JOHN SCHMIDTING, OF VIENNA, AUSTRIA-HUNGARY.

PROCESS OF PRODUCING PRINTING-CLICHE SAND HIGH-BELIEFS.

A ECIFICATION forming part of Letters Patent No. 725,879, dated April21, 1903.

Application filed June 28, 1900- Serial No. 21,969. (No specimens.)

1'0 all whom, it may concern.-

Be it known thatI, JOHN SOHMIDTING,a subject of the Emperor ofAustria-I-Iungary, residing at Vienna, in the Province of Lower Austria,in the Empire of Austria-Hungary, have invented certain new and usefulImprovements in Processes of Producing Printing-Cliches andHigh-Beliefs; and I do hereby declare the following to be afull, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

The process forming the object of the present invention enables theproduction of clichs for book and newspaper printing, as well ashigh-reliefs for stamping and watermarks, in a simple and cheap mannerfrom a photographic negative that can be taken direct if the drawing isexecuted in hatching, while otherwise it can be taken in the wellknownmanner under a graticule.

The process is carried out in the following manner: A layer of gelatinapplied on a glass plate and made sensitive to light-as, for example, byplacing the plate in a twenty-percent. solution of ammoniumbichromate-is exposed to an electric arc-light with constant are under afinished photographic plate (positive or negativeyof the kind described.The use of the electric light is absolutely required, because withsunlight the hatchings of the drawing or reproduction of the graticulewould not appear sufficiently sharp. After the exposure of the platesunder the finished photographic plate (positive or negative) they areplaced into an alcoholic silver-bath consisting of about ten to fifteenparts ofsilver nitrate dissolved in a sufificient'quantity.

of water and to which is added eighty-five to ninety parts of alcohol.They thus become covered witha layer of a non-conductive silver salt andthe bath does not swell the gelatin and allows it to be quickly dried.After drying it is exposed to the action of the vapors of sulfuretedhydrogen until a bright precipitate of sulfid of silver having ametallic luster-appears. In this manner on those portions of the plateacted upon by. light the shadows remain hard, While the others remainsoft and capable of being swollen by water. Thereupon the metallic layeris scraped off from the edges of the plate and the plate is put into awater-bath, which is changed frequently. Owing to the action of thewater on the layer of gelatin, this layer is swelled, and the swellingtakes place unequally, according to whether the water is acting upon theparts of the gelatin layer which have been exposed to light or on thosewhich have not been exposed. In this manner a relief-plate is obtainedwhose surface is coated with a salt that is electrically conductive andthat can be strengthened in a galvanic bath of any suitable saltsay asalt of copper, if needed and the galvano-plastic layer can then bedrawn off from the gelatin layer.

Olichs produced in the manner described may be used direct forbook-printingpurposes after having been suitably strengthened by fillingthe rear part of the same with cast metal; For newspaper printing onweb-printing presses only relief-films with a thin galvanic metalprecipitate are used, which are backed with a thin layer of stereotypecompound or the like in order that they may be easily fitted upon theprinting-roller of the web-printing press. q

In case the gelatin layer is submitted to but a short though very sharpexposure under the negative reliefs can be obtainedby the swelling ofthe gelatin layer, from which casts in gypsum may be taken, From thesegypsum casts metallic clichs may be ob-- tained by casting metallicalloys in the usual well-known manner, and these clichs can be used forstamping. i

In order to obtain clichs for water-marking in a dry manner, a positiveis obtained from the above-mentioned cast metallic clich by pressingsoftened celluloid into it.

2. The process, which consists in forming an actinic impression on asensitized film, subjecting the film to a solution of an electrically-.9 Having thus described my invention, what non-conductive silver salt,subjecting the film to the action of a suitable reagent to convert thenon-conductive silver salt into a conductive one,vand then swelling thefilm.

3. The process, which consists in rendering a gelatin film sensitive tolight, producing an actinic impression thereon,subjecting the film tothe action of a non-swelling solution of an electrically-non-conductivesilver salt, converting the silver salt on the film into a conductivesalt by a suitable reagent, swelling the film and electroplating theswelled film, substantially as set forth.

4. The process, which consists in rendering a gelatin film sensitive tolight, producing an actinic impression thereon,subjecting the film to analcoholic solution of silver nitrate, converting the silver nitrate intosulfid and swelling the film, substantially as described.

5. The process, which consists in rendering a gelatin film sensitive tolight, producing an actinic impression thereon,subjecting the film to analcoholic solution of silver nitrate, drying the film, treating the filmwith sulfureted hydrogen, swelling the film with water, electroplatingthe film with a suitable metal and removing the gelatin, substantiallyas described.

6. The process, which consists in producing an actinic impression upon agelatin film sensitive to light, strengthening the impression with anelectrically-conductive salt, swelling the film, electroplating theswelled film, making a cast from the plated film, obtaining a metalliccast from the first-mentioned one and then producing a printing-surfaceof celluloid from said metal cast, substantially as and for the purposesset forth.

In testimony that I claim the foregoing as my invention I have signed myname in presence of two subscribing witnesses.

JOHN SOHMIDTING.

'Witnesses:

ALVESTO S. HOGUE, AUGUST FUGGER.

